Associate, Structural Integrity Associates, San Jose, California
President, Corrosion Failure Analysis and Control, San Ramon, California
Pages: 19 Published: Jan 1997
Power plants have experienced severe general corrosion, pitting, under deposit corrosion, and microbiologically influenced corrosion (MIC) in cooling water systems, resulting in decreased plant availability and significantly increased operations and maintenance costs. MIC has been a particularly difficult problem since corrosion resistant alloys in relatively benign environments have failed as a result of microbiological influences in short times. Copper base alloys, carbon steels and stainless steels have all been susceptible. In a number of instances, replacement of piping and heat exchangers has been required to alleviate corrosion-related problems.
Monitoring is a key element to improved corrosion control in cooling water systems. On-line methods provide evaluations of corrosion rates in real time and are sensitive to localized corrosion. Electrochemical methods of corrosion measurement are readily automated, both for acquisition of corrosion data and for process control. An electrochemical probe for on-line monitoring of biofilm activity has been shown to provide an early warning of biofilm formation and incipient MIC in fresh and saline waters.
monitoring, biofilm activity, microbiologically influenced corrosion, electrochemical methods
Paper ID: STP11355S